is an eccentric trans-Neptunian object with a

centaur A centaur ( ; grc, κένταυρος, kéntauros; ), or occasionally hippocentaur, is a creature from Greek mythology with the upper body of a human and the lower body and legs of a horse. Centaurs are thought of in many Greek myths as being ...

-like orbit from the outer Solar System, approximately 150 kilometers in diameter. It was discovered on 21 July 1999, by astronomers John Kavelaars, Brett Gladman, Matthew Holman and

Jean-Marc Petit This is a list of minor-planet discoverers credited by the Minor Planet Center with the discovery of one or several minor planets (such as near-Earth and main-belt asteroids, Jupiter trojans and distant objects). , the discovery of 612,011 numb ...

Mauna Kea Observatories The Mauna Kea Observatories (MKO) are a group of independent astronomical research facilities and large telescope observatories that are located at the summit of Mauna Kea on the Big Island of Hawaiʻi, United States. The facilities are located ...

, Hawaii, United States.

Orbit and classification

orbits the Sun at a distance of 17.6–46.6 AU once every 181 years and 9 months (66,375 days). Its orbit has an eccentricity of 0.45 and an

inclination Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a Plane of reference, reference plane and the orbital plane or Axis of rotation, axis of direction of the orbiting object ...

of 3 ° with respect to the ecliptic. The body's

observation arc In observational astronomy, the observation arc (or arc length) of a Solar System body is the time period between its earliest and latest observations, used for tracing the body's path. It is usually given in days or years. The term is mostly use ...

begins with its official discovery observation at Mauna Kea in 1999.

Neptune Neptune is the eighth planet from the Sun and the farthest known planet in the Solar System. It is the fourth-largest planet in the Solar System by diameter, the third-most-massive planet, and the densest giant planet. It is 17 times ...

has a

semi-major axis In geometry, the major axis of an ellipse is its longest diameter: a line segment that runs through the center and both foci, with ends at the two most widely separated points of the perimeter. The semi-major axis (major semiaxis) is the long ...

of 30 AU and has a semi-major axis of 32 AU. The

Minor Planet Center The Minor Planet Center (MPC) is the official body for observing and reporting on minor planets under the auspices of the International Astronomical Union (IAU). Founded in 1947, it operates at the Smithsonian Astrophysical Observatory. Function ...

(MPC) does not classify this object as a centaur because the MPC defines centaurs as having a semi-major axis of less than 30.066 AU. crosses the orbits of both Neptune and

Uranus Uranus is the seventh planet from the Sun. Its name is a reference to the Greek god of the sky, Uranus (mythology), Uranus (Caelus), who, according to Greek mythology, was the great-grandfather of Ares (Mars (mythology), Mars), grandfather ...

and has an inclination of only 2.62°. The

Deep Ecliptic Survey The Deep Ecliptic Survey (DES) is a project to find Kuiper belt objects (KBOs), using the facilities of the National Optical Astronomy Observatory (NOAO). The principal investigator is Robert L. Millis. Since 1998 through the end of 2003, the sur ...

(DES) defines centaurs using a dynamical classification scheme, based on the behavior of orbital integrations over 10 million years. The DES defines centaurs as nonresonant objects whose osculating

perihelia An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion. General description There are two apsides in any ellip ...

are less than the osculating semimajor axis of Neptune at any time during the integration. Using the dynamical definition of a centaur, is a centaur.

Physical characteristics

In July 2009, a rotational lightcurve of was obtained from photometric observations. Lightcurve analysis gave a

rotation period The rotation period of a celestial object (e.g., star, gas giant, planet, moon, asteroid) may refer to its sidereal rotation period, i.e. the time that the object takes to complete a single revolution around its axis of rotation relative to the ...

of 9.26 hours with a brightness amplitude of 0.11 magnitude (). The period, however, is ambiguous with alternative solutions (13.4 and 15.45 hours).

Numbering and naming

This

minor planet According to the International Astronomical Union (IAU), a minor planet is an astronomical object in direct orbit around the Sun that is exclusively classified as neither a planet nor a comet. Before 2006, the IAU officially used the term ''minor ...

was numbered by the

on 22 August 2002. As of 2018, it has not been named.

Notes

References

External links

Asteroid Lightcurve Database (LCDB)
query form

)
Dictionary of Minor Planet Names
Google books

– Observatoire de Genève, Raoul Behrend

– Minor Planet Center * * {{DEFAULTSORT:1999 OX3 044594 044594 Discoveries by John J. Kavelaars Discoveries by Brett J. Gladman Discoveries by Matthew J. Holman Discoveries by Jean-Marc Petit 19990721